OBJECTIVES: The oncology market has become one of the major focus areas for pharmaceutical and biotech firms. As of March 2009, 15,752 of 39,747 Phase I,II, and III trials listed on clinicaltrials.gov, were related to cancer (approximately 40%). This large interest in oncology stems from market success of cancer therapies launched in the past decade and the existence of high unmet need to treat different types of cancers. As the number of FDA approved cancer therapies increases there is a need to understand treatment patterns of these cancer drugs. METHODS: To understand the trends in usage and sales of cancer therapies we analyzed the US market (sales and prescription) 2005-2008 data for all FDA approved cancer drugs. Drugs were categorized as targeted cancer therapies, chemotherapies, monoclonal antibodies, small molecules, branded and generics. RESULTS: During the past five years the usage of both targeted cancer therapies and chemotherapy drugs has increased by high double digit rates. From 2005-2008, the total prescriptions for targeted cancer therapies and chemotherapies increased by 66% and 30%, respectively.  While the sales of both types of these drugs are expanding, the majority of sales growth is attributed to an increasing uptake of targeted cancer drugs. The sales share of targeted cancer therapies in the US oncology market increased from 36% in 2004 to 56% in 2008. Among targeted cancer therapies, majority (more than 75%) of uptake belongs to monoclonal antibodies. CONCLUSIONS: The usage and sales trends show a significant increase in the use of cancer drugs. The high usage of targeted cancer therapies versus chemotherapies shows the rapidly changing nature of cancer treatment regimen.